Railway signaling system.



L; H. THULLEN.

[RAILWAY SIGNALING SYSTEM.

APPLICATION FILED FEB.5,1904..

Patented Sept. 8, 1914.

, mum Q I -55 E5 MN I I I w m u I 1 v. 5-: L v ER k I m H .q

LOUIS H. T-HU'LLEN, 0F EDGEWOOD PARK, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH& SIGNAL COMPANY," OF SWISSVALE', IPENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

RAILWAY SIGN Specification of To all whom it may concern Be it known that I, LOUIS HQIHULLEN, a citizen of the United States, residing at Edgewood Park, in the 'county of allegheny and State of Pennsylvania, haveinveritd or discovered new and useful Improvements Railway Signaling Systems, of which the following is a specification.

My invention relates to systems of railway signaling wherein the signals are op-- erated by an alternating signaling current in the track-circuits of the system. Both rails of the track are divided into insulated sections corresponding to block sections. The. railway cars may be propelled by a direct current or by an alternating current.

It is among the objects of my lIIVBIItIOIl'tO permitthe use of both rails as a return of the propulsion current and at the same time prevent the alternating current n the track circuits from passing from the track circuit of one block section to another.

Referring to the drawings, Figure l is a diagrammatic view of one form which my signaling system may assume. Fig. 2 1s a similar view of another form of my invention. Figs. 3 and 4 are details showing means for connecting the ends of the rail sections, differing fromthose shown on Figs. 1 and 2.

Referring to Fig. 1, A is a source of current, here shown diagrammatically as a source of direct current which supplies current to the trolley wire B. Any otherform of generator to supply car propulsion current may be substituted for the direct current generator A, for example an alternating current generator. If any such othergenerator be used, the signaling current will preferably be different-from the current supplied by such other generator in some characteristic. For example, if the generator A be an alternating current generator, its frequency will preferably be of a different frequency from the alternating signaling cur.-

rent. The source A of'current is. connected to the rails of the track through the induction coil P, on a core 79, the coil P being tapped at its middle point by the generator connection and having one end connected to one rail, and the other end to the other rail. 'l'hewindings are in such a direction-that the direct current does not unduly magnet- AIJING SYSTEM.

Letters Patent. Patented Sept. 8, 1914:.

Serial No. 192,145.

the alternating signaling current which controls the signal. The track is divided in block sections F, F, and F; the two rails being both divided at H into pairs of rail corresponding to the block sections F, F, and respectively. Each pair of rail secrail section except as they are electrically connected in the manner hereinafter indicated. D represents conventionally an electric car having thetr olley pole (Z and trolley d. L designates a source of signaling current, which preferably is of a different character from the car propulsion current.

cally, as being a source of alternating cur, rent which feeds the'leads 1 to which are connected in parallel the primaries of the transformers. E. The secondarye of each transformer is connected to the track rails of its block section, a transformer being associated with each block section or pair of rail sections.

Connected with the rails of each block section are the wires which *are connected to the relay K, which is operable by the alternating signaling current only. The arms In of the relays in the position shown bridge or connect the terminals 0 0 of the local circuits which control the signals C.

The track rails of adjacent bloc sections are connected by inductive windings M and N. As shown the windings M connect the rail sections f, f, and f, and the windings N, the rail sections f, f, and f". The windings M and N which connect the rail sections of adjacent block sections are associated in pairs with the same metallic core. The pairs of windings M and N are so wound on the core that the direct return propulsion currection thatthe magnetization of the core by the one winding is neutralized by the other. The return propulsion current traverses the rails and the windings constantly in one direction, while the alternating signaling current in any one block section traverses one rail in one direction at any rcction. Therefore, while the windingsM and N are such as to neutralize the effects of the direct current on the cores, the direction ize the core of the coil, but will choke down of the alternatingsignaling current through ,The source L is here shown, diagrammati :sections f and f, f and f andsft and tions is insulated from the adjacent pair of I rent on the track traverses them in such a di- 7 period and the other rail in the opposite dithe .combined-lturns is such as to cause the windings to become choke coils.

' The rails of each block section are con:

iiect'edby inductive windings or cross-bondings our low ohmic resistance to form paths for the car propulsion current, that may traverse the same owing to any difi'erence of potential of the car propulsion current that 'might exist between the rails.

Y windings The crossbondings being inductive are therefore traversed by a small'amount of the alternating, signaling current, andi-are 'used to. form a bond on the section to which it' is connected; so that an alternating signaling current of some definite amount traverses the induce tive windings M and N. Thel cross bonds may be used or noty asthe casewai'rants Fig. 2 is the same as Fig. 1','excep t that the windings M and N'" are cross connected between the adjacent block'sections as shown-L Here the return 1 propulsion current is transposed, the current on one rail section, as f, of one block section passing through one winding to 'a rail section, as f, han adjacent block section. In this formfif the rail insulation between adjacent, blocks should-breakdown, as between. block sections F and F the two rail sections each side of the defect would be short circuited, depriving the relay circuits of sbgmuch signaling current that they will beunable to hold their yarms is against the contacts '0. The opening of the local'circuits'causes the signals" 0 to indicatedanger,as they areso constructed as to indicate a clear trackflo'nly 'when the local circuit is closed. The form of invention shown in 'Fig. 2 has the advan-i tage of tending to neutralize the difference of direct current potential that might exist between the rails due to the proximity of the third rail or othersou'rce of current supply, If the car D should enter any block','fthe alternating signaling current which normally' flows through the relay K of that block will'largely pass through the wheels and axles of the car, thus short-circuiting.

the relay. As the relay holds the local signal circuit closed by the action of the alternating signaling current, the said localcir cuit will at once become opened and its signal thrown to indicate danger. In case one of the rails should break, it is clear that the signal would also indicate danger. As soon as the car passes from the block section or the break has been repaired the circuit through the relay will be restored, causing the local circuit to be closed and the signal to indicate a clear track.

In. Fig. 3, I have shown another method of connecting the railsof the block sections. I employ two induction coils, the windings M and M of coils being in series and join- .ing the adjacent ends of the same rail. The N and N of the coils are in series and connect the adjacent ends of the other rail. The windings M2, M8, n and N3 are rail sections" f and f Thedire'ction of the windings is such in the coils that this return 'currentleavesthe cores thereof practically.

unma'gnetized. The" signaling current on --the rail'seetions f'a'nd f, for example, will have 'a' paththrough the winding M the point m,"and" the winding N but as these f-windings arenin the same direction, only a 'sinall portion of the signaling current can therelay circuits In this form of my inven- 'tion the cross-connections of the rails form paths to equalize the differences of potential connected at the point m which is between the two induction coils. The point we is in fend 'f.;through ,the' windings M and N the "point andlthe win'dingsM and N to the take this path not enough to short circuit of the propulsion that may tend to exist in I portions of the track circuit.

In Fig. 4, I employ two induction coils to connect the rail sections. I have shown the rail. section f connected through the wind- "ing M to the rails'ection f and through the winding N to therail section i The rail 'section is similarly connected to the rail "section fand f through thewindings M and N Ehe direction orthe wlndings of 'currentrpassing through them will not ap- M and N for example,-being wound in the samefiirection will choke out practically. all of the alternating slgnaling current which would'seeh a return by wayof the windings M and"-N*.-- A car on a block section will eflectthe signals the same with the constructions shown on Figs. 3 and 4 as on Figs. 1

and 2. i v

Ii-do not desire to-he restricted to the details-shown but claim protection for such modifications as shall come fairly within the spirit and scope of my invention. Ihave usedith .words trolley wire but a third rail or .other'feeder would be obvious equivalents.

I have herein referred to thedevices {or apparatus between adjacent block sections for permitting the passage of propulsion current as induction coils. They may be also termed inductive devices, inductive windingsf reactances, reactance bonds etc.

these coils is such thatthe return propulsion" preciably 'magnetize their'co res- The coils .Hav'ing describedcniy :inventiomewhat I claim is p l 1. In anelectric railway signaling system i having closed track circuits; aplurality of block sections each havingrboth rails insu-. lated from both;rails ofnan adjacent :block section, a source of alternating signaling our;

' rent. for supplying each closed track circuit cent block section forpermitting the return propulsion current to flow-from'both rails of one block section to both rails of an adjacent block section.

2. In an electric railway signaling system having-closed trackcircuits, a plurality of block. sections each having bothirails insulated from bothirails of aniadjacent block section, a source-of alternating signaling current for supplying eacheclosed track circuit with an alternating signaling current, a signalfor .each block section controlled by .saidalternating signaling current, a sourceof currentfor; propelling the cars,- means comprising windings connecting the rails of onewblocksection with the opposite rails. of an, adjacent block section for permitting the return propulsion current to flow from both rails of one block section to both rails of an adjacent block section, and a cross inductive winding for each-block section.

3. The combination in an electric railway system, a source of car propulsion current; vehicles operated thereby; a circuit for said car propulsion current comprising two conductors with which the car makes movin contact, one of which is formed by the track;

means for dividing the track to formblock sections; signal circuits, at least one for each other turns of said windings.

i. In an electric railway signaling system, closed track circuits, a. plurality of block sections, each having both rails insulated, a

source of current for supplying the rails of each block section with signaling current, a signal for each block section controlled by said signaling current, a source of direct current for propelling the cars, and a plurality of inductive devices connecting the ends of adjacent rail sections, each inductive device consisting-ofia pair of windings ch -a core, the;two=rails of one block section being connected by one pairof said windings and the railsofthe adjacentblock section being connected byanotherpair thereof, the two pairs being electrically; connected, thewindings beingsuch that the members of each pair are inductive to the signal current and that the-propulsion current flowing in. said members causes opposing magneto-forces.

5. In a signalingsystem for electric railways, the combination with a. plurality of block sections both track rails of which are insulated, of a' track circuit for each block section; a source of alternating current supply for each track'circuit; a source of ourrentfor propelling the cars, the track rails of the block sections forming a return path therefor; and means between adjacent block sections for permitting propulsion current to pass from the track rails of one block section. to the track rails of another block section .and said means being formed to be unaffected by the passage .of the propulsion current through it by-reason of opposing magnetic effects created thereby. i

6. In a signaling system for electric railways, the combination with a plurality of block sections both ,rails of which are insulated,.of a track circuit for each block sec- 0 tion, a source of alternating current supply for each track circuit, a source of direct current for propelling the cars, the track rails of the block sections forming a return path therefor; and'means between adjacent block sections for permitting propulsion current to pass from the track rails of one block sec- 1 tion to the track rails of another block section, and said means being formed to be unafiected by the passage a direct propulsion current through it by reason of opposing magnetic effects created thereby. 7. In an electric railway signaling system, thecomloination with a plurality of block sections electrically insulatedfrom each other, a. track circuit for each block section, a source of alternating current for each track circuit, a relay for each track circuit, a source of current for propelling the cars, a plurality of inductive devices connecting the ends of adjacent rail sections, said devices forming paths oflow ohmic resistance to the propulsion current'nnd of high impedance to the alternating current, and conductors connecting adjacent inductive devices.

8. In combination, a. source of power current; a feeder conductor extending therefrom; a return conductor leading thereto and formed in part by the track rails of a railway; insulation in both track rails for dividing the railway into block sections; inductive bonds connecting the opposite rails of the several block sections; conductors connecting adjacent .bonds whereby a waste for. electric railways, embodying two rails divided into sectionsby insulated joints, re-

middle points of the two coils at ac'tance bonds arranged to bridge said joints, said bonds each provided with a coil connected flfll'OSSilihQ trafiic rails, and bonds of adjacentsections connected together at- -their centers. 4 l

. in ..i.

10. A system of-automatic block signaling for electric. railways,-embodying two rails divided 'intosections by insulated joints, a reactancesbondatzthe oppositeends 'of each section, said bonds'each consisting of a core and a-coil thereon said coil connected across the trailic rails, and aiconductor connecting the centers of thecoils on opposed bonds in adjacent track sections together.

11. A system'of automatic block signaling for electric railways, embodying two vrails divided into sections by insulated joints, bonds arranged to bridge said joints, said bonds each having-a core and a coil thereon,

said coil connected across the trailic rails,

and-twoadjacent bonds connected together at their centers.

12. In a system of automatic block signal ing for electric railways, the combination of two electrically continuous rails divided into sections by a breakin each rail at the end of each section, the ends of the two rails of a section connected across by a coil, the the end of a section connected together. 13. In a system of automatic block signal ing for electric railways and in combination with the traflic rails each divided into block sections by'insulated joints, reactance bonds each bond comprising acore, a coil thereon connected'across the .trackway, and a conductor connecting the middle point of the coils on adjacent bonds.

14, In a system of automatic block signal ing for electric railways, and in combination with'the trafiic rails each divided into block sections by insulated joints, reactance bonds 'the middle point of the coils on adjacent bonds.

16. In a system of automatic block signaL nectedat its terminals-to the opposite rails of a section, and a conductor leading from the middle point of said coil. 17. -In-a-systemof automatic block signaling for electric railways and'in combination with :the traffic rails each divided into block sections by insulated joints,reactance bonds,

each comprising a core and aicoil thereon, the coils being connected across the track rails, and conductors connecting the middle points of adjacent coils. v

. 18. A reactance bond comprising a core, a winding having a number of turns surrounda middle point of said-winding. I

19. A reactance bond comprising a core, a Winding thereon having. all its. turns in'the same direction, and a conductor leading from the middle pointof said winding-1 ing said core, and a conductor leading from 3 720;A reactance bond comprisinga core, a

winding thereon, and a connection from the middle point of'said winding whereby when equal currents are sent in opposite directions into said winding from its ends and out-at its middle, or vice versa, equal and opposite magneto-motive forces will be produced.

21, The combination with the elements of an. automatic block signaling'system' such as described, of reactancebonds situated at the ends ofcthe block, sections,'each bond comprising a magnetic core, winding connected across thev rails, and a'connectiom leading from the middle point of said winding.

.22. An electric railway signaling system having track circuits, insulated rail joints in each rail to electrically separate the track circuits, and a source of current supply for the propulsion of cars upon the railway, in combination with inductive cross bonds connected in pairs from rails on one side of the track to rails on the opposite side of the same track, an electric connection from one cross bond of a pair. so connected to the other cross bond of the same pair, the two inductive cross bondszbeing located respectively on opposite sides of a air of insulated rail joints, and forming with the said'electrical connection a pair of inductive rail bonds across the said pair of rail joints, substantially as described.

23. An electric railway signaling system having track circuits, insulated rail joints to electrically separate the track circuits, a source of current supply for propulsion current, in combination inductivecross bonds having high impedance'to a signaling current and low ohmic resistance to a propul- "'sion current connected in pairs from rails the said joints andthe other of said cross bonds being on the other side of the said joints, and an electric connection from, a

point at or near the center of one of the said cross bonds, to a point at or near the center of the other of said cross bonds, the said electric connection forming in conjunction with one part of each cross bond a rail bond around one of thejoints, and forming in conjunction with the remaining parts of the cross bonds a rail bond around the other joint, substantially as described.

24. An electric railway inwhich thetrack rails are used as a return path for car propulsion in combination with a source of electric energy for propelling the cars on said' railway, insulated joints in both rails to form electrically insulated track sections, a source of current and devices connected therewith for supplying signaling current to the isolated track sections, and inductive devices adjacent each pair of rail joints connected with the track rails and to each other to conduct car propulsion current around said adjacent insulated joints from one track section to the next adjacent, but not the signaling current.

In an electric railway system, a source of power current; Vehicles operated thereby; a circuit for said power current comprising two conductors with which the vehicles make moving contact, one of which is 7 ing current for each signal circuit connected to both rails; a signal device for each signal circuit and completing such signal circuit; an inductive bond located at each end of eachsection, each comprising a core and a winding which is connected with the track rails; and means connecting the windings of adjacent bonds intermediate'the'ir ends whereby the car propulsion current will be conducted from the rails of one section to the rails of the adjacent section and under normal conditions will exert opposite magnetic effects on the cores of the inductive bonds.

, 26. In an electric railway system, a source of power current; vehicles operated thereby; a circuit for said power current comprising two conductors with which the car makes moving contact, one of which is formed by the track; means for dividing the track to form sections; signal circuits, at least one for each section, of which the rails of the track form both sides; a source of signaling current for each signal circuit connected to both rails; a signal device for each signal circuit and completing such signal circuit;

means located at each end of each section for conducting the car propulsion current from the rails of its section to the rails of an adjacent section each comprising a winding electrically connected with the rails of its section, a core for each winding, and an electr cal 'connectlon between ad acent wlndlngs 'intermedlate their ends so that under normal conditions the car propulsion current will exert opposite magnetic effects on the cores, butthe signa ling current will exert cumulativeeffects; I

27. In an electric railway system, a plurality of track sections; a closed track circuit for each tracksection; a source of signaling current for each track circuit; a

source of propulsion current for vehicles traveling along the railway; an inductive bond located at each end of each track section comprising a Winding which is connected with the opposite rails of its track section; and a conductor connecting substantially the middle points of adjacent windings.

28. In a combined system of power transmission and signaling for electric railways, a source of power current; transmitting conductors therefor, one of which normally comprises two equipotential conductors act-- ing jointly to transmit power current simultaneously in the same direction; means for dividing said equipotential conductors into sections; a source of signaling current connected to each section whereby the two conductors thereof act to transmit signaling current in opposite directions; a signaling device connected with each section; windings connected across the conductors of each section; and a conductor connecting equipotential points in the said windings at ad' mit the power current from one section to another.

29. In a combined system of power transmission and signaling for electric railways, a source of power current; transmit-ting conductors therefor, one of which normally comprises two equipotential conductors actmg olntly to transmit power current simultaneously in the same direction; means for dividing said equipotential conductors into sections; a source of signaling current connected to each section whereby the two conductors thereof act to transmit signaling current in opposite directions; a signaling device connected with each section; inductive windings connected across the conductors of each section; and a conductor connecting equipotential points in the said inductive windings at adjacent ends of sections and serving to transmit the power current from one section to another.

30. The combination with two traflic rails of a railway both of which are divided by vices-located between the traific rails of each a source of power current; transmitting conlines of track rails for dividing the rails which windings is connected to one rail and flowing therethrough opposing .the maginsulation to form sections, andwhich act jointly to conduct car propulsion current. simultaneously in the same direction; of deinto sections; a source of alternating signaling current connected across the rails of each section; and means located at each junction of adjacent sections for conducting the propulsion current from the rails of one section to the railsof the other s'ection, said means comprising windings, one terminal of one of another terminal of one of which windings is connected to the opposite rail, the magneto-motive force produced in said means by the propulsion current in one rail neto-inotive force. produced by the propulsion current in the other rail flowing therethrough, and the magneto-motive force produced in said means by the signaling current flowing fromone rail to the other being all in one direction.

32. In a combined system of power trans- 7 mission and'signaling for electric railways;

signaling current connected to each section whereby the traflic rails thereof act to transmit signaling current in opposite directions; inductive windings connected across. the traflic rails of each section; and a conductor connecting equipotential-points in the said windings at adjacent ends of sections and serving to transmit the power current 'from one section to another.

83. In a combined system of power transmission and signaling for electric railways; a source ofpower current for propelling the cars; transmitting conductors therefor, one of which comprises the two traflic rails acting'jointly to transmit power current simultaneously in the same direction; insulating means dividing both traflic rails into sections; a source of signaling current connected to each section whereby the traflic rails thereof act to transmit signaling current in opposite directions; and a plurality of inductive devices connecting the ends of" adj acent sections, each inductive device comprising a pair of windings which are con nected together in series across the trailic rails of its section, and an electrical com nection between inner ends of adjacent pairs of windings. Signed at Pittsburgh this 2d day of February, 1904. j LOUIS H. THULLEN.

'Witnesses:

F. N. BARBER, A. M. STEEN. 

